WHAT: Debate among Republican candidates for presidentWHEN: 8 p.m. to 10 p.m. tonightWHERE: Sheslow Auditorium, Drake University. All tickets are sold out.WHO: Six candidates will participate: Michele Bachmann, Newt Gingrich, Ron Paul, Rick Perry, Mitt Romney and Rick Santorum. Jon Huntsman did not meet criteria tied to standings in state and national polls.HOSTS: ABC News, local affiliate WOI-TV, The Des Moines Register, Yahoo and the Republican Party of Iowa.MODERATORS: ABC News anchors Diane Sawyer and George Stephanopoulos.HOW TO WATCH: Airs nationally on the ABC television network and in central Iowa on WOI-TV, Channel 5. Will be livestreamed by those sources and here, at DesMoinesRegister.com/caucus.PROTESTS: Occupy Des Moines protesters plan to be on the scene.

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Dianne Bystrom, director of the Carrie Chapman Catt Center for Women and Politics at Iowa State University.

Graham Gillette, a public affairs and communications consultant who worked in the George W. Bush administration but caucused for Barack Obama in 2008. He’s a featured blogger on politics at DesMoinesRegister.com.

Timothy Hagle, associate professor of political science at the University of Iowa.

Steffen Schmidt, professor of political science at Iowa State University and a featured blogger on politics at DesMoinesRegister.com.

Shane Vander Hart, who works in youth ministry and is editor of the Caffeinated Thoughts blog and a featured blogger on politics at DesMoinesRegister.com.

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Replay the debate live chat with political experts.

First of ‘Conversations’ programs

Texas Gov. Rick Perry will be interviewed by Des Moines Register political columnist Kathie Obradovich on Sunday in the first of a series of one-on-one conversations with the presidential candidates.

The half-hour programs are produced in partnership with Iowa Public Television.

The first program, “The Candidates: Rick Perry,” can be viewed live here and iptv.org at 11 a.m. Sunday. It will be broadcast statewide on IPTV at 6:30 p.m. Monday.